A depth camera system or a range camera can be used to capture depth information about a scene. In particular, a depth camera system can generate a two-dimensional image or “depth map” where each value in the image corresponds to the distance between the depth camera and a portion of the scene that is in the field of view of the camera. The depth information may also be referred to as three-dimensional information, and the resulting depth map may be referred to as a three-dimensional reconstruction of the scene. This can be contrasted with a traditional camera, which captures the amount of light received from portions of the scene in the field of view of the camera, but not the distances of the objects and other features of the scene.
One class of depth camera systems uses a projection system or projection source to assist in the reconstruction of the depth information by projecting light onto a scene. Such systems may be referred to herein as being “active,” as contrasted with “passive” depth camera systems that do not include a projection system. These include: projecting an encoded pattern, such as those commonly used in structured-light methods; projecting a pattern to create a texture on the scene; and projecting a pattern that is designed or optimized for three-dimensional reconstruction. Projecting a texture or a pattern designed for three-dimensional reconstruction is typically used with systems that include two or more cameras.